Frequently, when humans interact with systems, processes and/or organizations intermittently, they interact on a recurring basis. Although such interactions are separated in time, they are often part of a long running transaction made up of several connected interactions. For instance, a person may join a discount club and get a membership token (e.g. a membership number) that is a required element in every purchase. There are many examples of using tokens for identification, entitlement, or associating a token holder with a transaction. Another common example is when a customer contacts a service agent for support. In most cases the service agent will provide the customer with one or more tokens to be used in future interactions which refer back to the original request for service. Similarly, tokens are widely used in the computer industry to correlate activities that are completed in multiple units of work that need to be associated with each other (e.g. Return Authorization Numbers used when a consumer wishes to return or service computer parts). Many of the generated tokens are directly exposed to humans.
There are many challenges associated with the generation and use of tokens when communicated by humans using, for example, verbal or written communication. For example, when a customer calls a service agent on the phone, the service agent may verbally communicate a token to the customer. In most cases, the customer will need this token to successfully complete future interactions, and therefore retains the token in some manner. To retain the token, the customer may rely on one or more of: memorization, audio recording, hand-written transcript, typed transcript, or even depend on someone else to persist the token.
One common failure mode for scenarios that involve the transfer of tokens from (or to) a user is inadvertent transformation of the token. For instance, a verbally transferred token may be miscommunicated when it contains a combination of upper and lower case characters. In addition, verbal transmission of tokens involving words are subject to substitution errors involving similar sounding words (e.g. when two or more words are homonyms with respect to each other). When tokens are typed, or written, the shapes of the symbols are also subject to misinterpretation; for instance, the difference between the numeral one and the lower case letter “L” are indistinguishable in some people's handwriting, as well as in some printed fonts.
Numerous mechanisms have evolved to minimize the occurrence of such harmful transformations. For instance, the NATO Phonetic alphabet (Allied Tactical Publication ATP-1, Volume II: Allied Maritime Signal and Maneuvering Book, NATO, 1983) uses a well distinguished word to represent each letter of a token. In addition, some printed fonts and styles of hand writing represent each character uniquely; for example, placing a slash through a numeral zero in order to distinguish it from a capital letter “O” when typed or handwritten.
These mechanisms, however, fail to uniformly address verbal and written communication. For example, the NATA Phonetic alphabet addresses written communication, but not verbal communication. In addition, many of these mechanisms rely on an alphabet that may be unfamiliar to a customer.